Abaixo está uma instrução que descreve uma tarefa de geração de SQL, combinada com uma entrada que fornece mais contexto sobre os esquemas de tabela disponíveis. Escreva o código SQL que responda adequadamente à solicitação
 ###Instrução: Qual é a aparência do Polifenil Éter de oxitiol de 3 e 4 anéis?
 ###Tabelas: CREATE TABLE 2009 (2009_id AUTO_INCREMENT PRIMARY KEY, Tournament VARCHAR, Winner VARCHAR, Runner-up VARCHAR, Score VARCHAR, Third Place VARCHAR) CREATE TABLE 2011_classic_superbike_practice_times_and_leaderboard (2011_classic_superbike_practice_times_and_leaderboard_id AUTO_INCREMENT PRIMARY KEY, Rank INT, Rider VARCHAR, Sat 20 Aug VARCHAR, Mon 22 Aug VARCHAR, Tues 23 Aug VARCHAR, Wed 24 Aug VARCHAR, Thurs 25 Aug VARCHAR, Fri 26 Aug VARCHAR, Sat 27 Aug VARCHAR, Mon 29 Aug VARCHAR, Wed 31 Aug VARCHAR) CREATE TABLE doubles:_7_5_titles_2_runners-up (doubles:_7_5_titles_2_runners-up_id AUTO_INCREMENT PRIMARY KEY, Outcome VARCHAR, Year INT, Championship VARCHAR, Surface VARCHAR, Partner VARCHAR, Opponents VARCHAR, Score VARCHAR) CREATE TABLE physical_properties_of_ppes (physical_properties_of_ppes_id AUTO_INCREMENT PRIMARY KEY, Polyphenyl Ether VARCHAR, Appearance VARCHAR, Thermal Stability °F (°C) VARCHAR, Viscosity (cSt) at 100°F (38°C) INT, Viscosity (cSt) at 210°F (99°C) INT) CREATE TABLE season_3_1957_58 (season_3_1957_58_id AUTO_INCREMENT PRIMARY KEY, Series # INT, Season # INT, Title VARCHAR, Director VARCHAR, Writer(s) VARCHAR, Airdate VARCHAR)  
SELECT Appearance FROM physical_properties_of_ppes WHERE Polyphenyl Ether = 3- and 4-ring oxythio